Now with the brief look at the GCC 4.7 Sandy Bridge performance out of the way, here's a look at LLVM/Clang 3.0 and then LLVM/Clang 3.1 from their SVN repository. The same test system, software configuration, and test parameters were used. The SVN revision is 148223.
C-Ray under LLVM-Clang 3.1 SVN is also faster than the stable 3.0 release, similar to the improvement found in moving from GCC 4.6 to 4.7 but not as large.
Likewise, POV-Ray is also faster with the current code to form the basis of the LLVM 3.1 release.
The libvpx VP8 benchmark looks like it is trying to push ahead on LLVM-Clang 3.1.
The LAME MP3 test might be in store for some improvements that would be more noticeable with the slower Intel Sandy Bridge processors.